Device for implanting a prosthesis in a tissue

ABSTRACT

A device for implanting a prosthesis  12  in a body tissue equipped with a tubular element  7 , within which a prosthesis  12  can slide, and a pressure element  16  for moving said prosthesis  12 . The device also comprises a cartridge  5  provided with a seat  31  at its interior, such seat housing the prosthesis  12  and movable under the action of a pusher element  13  from a first position, in which the seat  31  is not facing the tubular element  7 , to a second position, in which the seat  31  is in communication with the tubular element  7  in order to allow the insertion of the prosthesis  12  inside the tubular element  7  upon command of the pressure element  16.

The invention concerns a device for implanting a prosthesis inside atissue delimiting a channel of the human body, in order to cause anarrowing of such channel, i.e. a reduction of the relative crosssection. The invention also concerns a functioning method for thedevice.

The device according to the invention can be used for example forimplanting the prosthesis close to the anal canal, if it is desired todecrease the size of the relative cross section in order to treat apatient affected with fecal incontinence.

Alternatively, the device according to the invention can be used forimplanting the prosthesis in tissues delimiting the urinary canal. Thenarrowing deriving therefrom is useful for treating a patient affectedwith urinary incontinence.

In addition, the device according to the invention can be used forimplanting the prosthesis in the mucous of the esophagus if it isdesired to treat a patient affected by gastro-esophagus reflux.

The prosthesis implanted by using the device according to the inventioncan be obtained in a known polymer material such as hyexpan, i.e. amaterial having the capacity to absorb high quantities of liquid andconsequently be swollen. When a prosthesis of this type is implanted ina tissue that delimits a channel of the patient's body, the materialconstituting it absorbs the body liquids, causing a swelling of theprosthesis itself. In such a manner, the narrowing of the channel isproduced, whose free cross section decreases. The passage of substances,liquids or solids through the channel is consequently blocked.

US 2002/0052653 describes a device for implanting a prosthesis close tothe gastroesophageal junction of a patient. The device comprises ahollow member, at whose interior a passage is provided in which one ormore prostheses can be received to be implanted in the body of thepatient. The device also comprises a pusher element, arranged inside thehollow member and movable with respect to the latter, so as to make theprosthesis exit through a distal end of the hollow member, in order toposition the prosthesis at the desired point of the patient's body.

In order for the prosthesis to exit outward from the distal end of thehollow member, it is possible to push the pusher element towards thedistal end. Alternatively to that stated above, it is also possible toretreat the hollow member towards the operator while the pusher elementremains in contact with the prosthesis.

A first defect of the device described in US 2002/0052653 is that suchdevice does not ensure a precise positioning of the prosthesis in thebody of the patient, particularly when the hollow member is retreatedwith respect to the pusher element. Indeed, the hollow member might notbe retreated enough, in which case the hollow member is stopped while aportion of the prosthesis is still situated therein. If this occurs,when the operator moves the device away from the body of the patient,the prosthesis tends to be driven by the hollow member and its positionis consequently altered in an undesired manner.

It is also possible that the opposite situation occurs, i.e. that thehollow member is overly retreated with respect to the pusher element.This situation is problematic, especially if multiple prostheses arepresent inside the hollow member, such prostheses arranged behind eachother in order to be inserted in the body of the patient in subsequentinstances. Indeed, if the hollow member moves back too much, not onlydoes the desired prosthesis exit therefrom but also a portion of thesuccessive prosthesis. The latter, in contact with the body liquids, isswollen and can no longer be fully reinserted inside the hollow member.

A second defect of the device described in US 2002/0052653 is that suchdevice does not isolate the prosthesis during the steps in preparationfor the insertion of the same in the patient's body.

During the insertion and positioning of the hollow member inside thehuman tissue, blood, organic liquids and tissue fragments might enterinside the hollow member until they come into contact with theprosthesis.

The contact of the blood and the organic liquids with the prosthesis cangenerate the swelling of the same, before this has exited outward fromthe hollow body, with consequent difficulty in sliding inside the hollowbody.

In some case, the swelling of the prosthesis can generate the occlusionof the hollow body and phenomena of pointing of the prostheses insidethe hollow body.

In order to avoid the abovementioned problems, it is possible topreliminarily carry out the insertion of the hollow body and thepositioning of the same in the human tissue, and subsequently proceedwith the insertion of the prosthesis in the hollow body.

Such method is not free of risks of infection of the prosthesis from abacteriological standpoint.

In addition, the aforesaid successive loading of the prosthesis rendersthe surgical operation difficult and imprecise, lengthening theoperating times and complicating the operating steps of the operation.

Another defect of the device described in US2002/0052653 is theconformation of the terminal portion adapted to penetrate the bodytissue in order to generate, inside the same, the prosthesis insertionchannel.

The hollow conformation of the terminal portion does not allow theisolation of the tubular body interior from blood, organic liquid andtissue fragments.

In addition, the hollow internal conformation and the asymmetricexternal conformation does not facilitate the insertion of the hollowelement inside the body tissue.

One object of the invention is to improve the devices for implantingprostheses, particularly prostheses of the type capable of absorbing aliquid and consequently swelling, in a human tissue, particularly atissue delimiting a body channel, so as to cause a narrowing of thechannel.

A first object is to provide a device which allows precisely positioningthe prostheses in the tissue.

Further object is to reduce the risk that, when one implants aprosthesis in a tissue, the prosthesis is not completely released insidethe tissue, or reduce the risk that a portion of a possible successiveprosthesis is also released.

A second object is to provide a device that allows isolating theprostheses before their placement inside human tissue.

Another object is to provide for a device, bearing at least oneprosthesis, adapted to limit as much as possible the contact between theprosthesis and organic liquids released by the body tissue.

A third object is to provide a device which allows an easy insertion ofthe tubular body in the body tissue, protecting the integrity of theprosthesis.

The invention can be better understood and actuated with reference tothe enclosed drawings, which illustrate an exemplifying and non-limitingembodiment thereof, in which:

FIG. 1 is a perspective view showing a device for implanting aprosthesis in a tissue delimiting a body channel of a patient;

FIG. 2 is an interrupted perspective view, showing a front portion of anapplicator pistol included in the device of FIG. 1 and a cartridgeinsertable in the applicator pistol;

FIG. 3 is a section, taken along a vertical longitudinal plane, showinga front portion of a second embodiment of the device of FIG. 1 in afirst trigger position;

FIG. 4 is a section, taken along the plane IV-IV of FIG. 3, showing thefront portion of a second embodiment of the device of FIG. 1 in a restposition, if the device is obtained according to a first embodiment, orin an advance position if the device is obtained according to the secondembodiment;

FIG. 5 is a section like that of FIG. 3, showing the front portion ofthe device of FIG. 1 in a back position;

FIG. 6 is a section like that of FIG. 3, showing the front portion ofthe device of FIG. 1 in a loading position;

FIG. 7 is a section like that of FIG. 4, showing the device of FIG. 1 ina release position;

FIG. 8 is a section like that of FIG. 3, showing an upper portion of thedevice of FIG. 1 at the end of the aforesaid release position.

FIG. 9a is a cross section taken along the plane I-I of FIG. 3illustrating a particular structural detail of the cartridge in a firstposition.

FIG. 9b is a cross section taken along the plane II-II of FIG. 5illustrating a structural detail of the cartridge in a second position.

FIG. 9c is a cross section of a second variant of the cartridge in anintermediate time instant with respect to that of FIG. 9a and that ofFIG. 9 b.

FIG. 1 shows a device 1 for implanting a prosthesis in a body tissue,particularly in a tissue that delimits a channel of the body of apatient, e.g. the anal canal, or the urinary canal, or the esophaguscanal.

The prosthesis is shown in particular in FIG. 8, where it is indicatedwith the reference number 12. The prosthesis 12 can have elongatedshape, e.g. cylindrical or prismatic, and it can be obtained withso-called hyexpan material.

Said prosthesis 12 preferably has elongated form with extensiondirection along an axis Y-Y.

Said prosthesis 12 has cross section with area T and preferably hascylindrical shape.

The prosthesis 12 has a front end 19, which first exits outward from thedevice 1, and a rear end 20, which exits outward from the device 1 last.The front end 19 and the rear end 20 are placed at a mutual distance DL,which defines a longitudinal size of the prosthesis 12.

The device 1 comprises an applicator pistol 2, whose border wasindicated with a dashed line in FIG. 1 for the sake of clarity. Theapplicator pistol 2 is provided with a grasping portion 3, adapted to begrasped by an operator, and an operative portion 4, in which themechanisms are housed that allow moving the prosthesis 12. The graspingportion 3 is projected from one side of the operative portion 4,transverse with respect to a main direction along which the operativeportion 4 is extended.

The device 1 comprises a cartridge 5, more visible in FIG. 2, adapted tobe mounted in a front terminal region 6 of the applicator pistol 2. Thecartridge 5 comprises a tubular element 7 which, during use, isprojected from the front terminal region 6.

Said tubular element 7 defines a channel Z at its interior; such channelhas extension direction along a first axis X-X and cross section witharea A, within which the prosthesis 12 can slide.

The tubular element 7 is provided with an open end 18, through which theprosthesis 12 can exit outward. The open end 18 is the end of thetubular element 7 arranged in a position far from the applicator pistol2.

The cartridge 5 also comprises a support body 8 adapted to be introducedinside a hole 9 obtained in the frontal terminal region 6. The tubularelement 7 is projected from a first end of the support body 8.

Said support body 8 defines a chamber C at its interior; such chamber isin liquid communication with the channel Z and comprises a seat 31,housing a prosthesis 12, movable inside the chamber C and described inmore detail below.

The support body 8 can be equipped with fixing means 10 adapted to allowthe cartridge 5 to be fixed to the applicator pistol 2. The fixing means10 can comprise a tongue that is projected from a second end of thesupport body 8, the tongue being adapted to be engaged, e.g.snap-engaged, with a laminar element 11 of the applicator pistol 2, asshown in FIG. 3.

The tubular element 7 is slidable inside the support body 8 in adirection substantially parallel to an extension axis X-X of the tubularelement 7, as will be explained in detail below.

As shown in FIG. 3, the device 1 comprises a pressure element 16,adapted to act on the rear end 20 of the prosthesis 12 in order to pushthe prosthesis 12 towards the body tissue where it must be inserted.Said pressure element 16, defined by a cylindrical body, has extensiondirection along an axis K-K parallel and coinciding to the extensionaxis X-X of the tubular element.

The pressure element 16 is slidable inside the tubular element 7.

In other words, the pressure element 16 is movable inside the channel Zin order to move the prosthesis 12.

In a first embodiment, the device 1 can be directly provided with theassembled cartridge 5.

In such case, the pressure element 16 is inserted inside the tubularbody 7 (FIG. 4).

In a second embodiment, the device 1 can be provided with the cartridge5 disassembled.

In such case, the pressure element 16 can be initially housed in theapplicator pistol 2 in a manner such that, when the cartridge 5 ismounted on applicator pistol 2, the pressure element 16 is aligned withthe tubular element 7 (FIG. 3).

As shown in FIG. 4, the pressure element 16 can be shaped like a needleand can be provided with a pointed end 17, adapted for piercing bodytissue.

Said pointed end 17 is preferably closed in order to prevent blood andbody tissue from entering inside the tubular body 7 and coming intocontact with the prosthesis 12.

Said pointed end 17 has axial-symmetric extension with respect to theextension axis K-K of the pressure element 16.

In other words, the pointed portion 17 preferably has frustoconicalshape with symmetry axis coinciding with the extension axis K-K of thepressure element 16.

In addition, the open end 18 of the tubular element 7 has taperedconformation towards the vertex of the pointed portion 17 of thepressure element 16.

The configurations of the pointed end 17 and the open end 18 preventfragments of body tissue from entering inside the tubular body 7 duringthe insertion of the same inside the tissue.

In such a manner, during the sliding of the prosthesis 12 inside thetubular element 7, the fragments do not occupy the space between theexternal surface of the prosthesis 12 and the internal surface of thetubular element 7.

Consequently, the sliding of the prosthesis 12 inside the tubularelement occurs without pointing and through the use of low-powermotorized means.

The support body 8 can also comprise, in the second embodiment, alocking element 15, visible in FIGS. 3 and 4, for example having theform of a cylinder, possibly internally hollow. The locking element 15is housed in a slidable manner inside the tubular element 7, so as to bealigned with the pressure element 16. In particular, the locking element15 can be pushed towards the open end 18 by the pressure element 16, soas to be removed from the device 1.

More precisely, the locking element 15 has at least one hollow terminalsection 15 a, facing the pressure element 16, in order to allow thepointed end 17, during the movement of the pressure element 16, toengage the locking element 15 in order to push it outside the tubularelement 7.

In other words, when the pressure element 16 impacts the locking element15, its pointed end 17 is inserted inside the hollow terminal section 15a, facilitating the engagement of the pressure element 16 with thelocking element 15.

The function of the locking element 15 will be better explained below.

As shown in FIG. 3, inside the support body 8, the seat 31 is obtainedin which a prosthesis 12 can be housed that is ready to be implanted inthe body of the patient.

Said seat 31 has extension direction along an axis H-H, coinciding withthe extension axis Y-Y of the prosthesis 12, and cross section with areaV.

A pusher element 13 is active on the seat 31, inside the cartridge 5.

Said pusher element 13 facilitates the movement the seat 31, inside thechamber C, from a first position to a second position.

More precisely, said pusher element 13 is defined by elastic means 14adapted to generate a push of the seat 31 from the first position to thesecond position.

Said elastic means 14 facilitate a push of the seat 31 according to apush direction S incident on the first axis X-X of the channel Z.

In the first position, the seat 31 is not facing the channel Z.

As illustrated in FIG. 9a , in said first position the area V of thecross section of the seat 31 is outside the area A of the cross sectionof the tubular element 7.

In other words, the area V of the seat 31 does not intersect the area Aof the tubular element.

In such time instant, the area of the cross section T of the seat 12 isoutside the area A of the cross section of the tubular element 7.

In the case of prosthesis 12 with elongated form, housed in the suitablycounter-shaped seat 31, the axis X-X of the channel Z in said firstposition is misaligned with respect to the axis H-H of the seat 31.

Still more in detail the axis H-H of the seat 31, and hence the axis Y-Yof the prosthesis 12, is parallel to the first axis X-X of the channel Zbut does not coincide with the same.

The arrangement of the axis H-H of the seat 31, and hence of theprosthesis 12, with respect to the channel Z allows preventing theliquid communication between the channel Z and the seat 31.

This prevents the organic liquid, during the operations of insertion ofthe tubular element 7 inside the tissue, from flowing inside the channelZ and reaching the seat 31—hence coming into contact with the prosthesis12.

In the second position, the seat 31 comes into communication with thechannel Z.

Come illustrated in FIG. 9c , the area V of the cross section of theseat 31 at least partly intersects the area A of the cross section ofthe tubular element 7. In such time instant, the communication betweenthe channel Z and the seat 31 is facilitated, adapted to ease theinsertion of the prosthesis 12 inside the channel Z upon command of thepressure element 16.

If the area V of the cross section of the seat 31 is greater than thearea A of the cross section of the tubular element 7, the secondposition, assumed by the seat 31, is illustrated in FIG. 9 c.

If the area V of the cross section of the seat 31 is lower, orsubstantially equal to the area of the cross section of the tubularelement 7, the second position assumed of the seat 31 is illustrated inFIG. 9 b.

In both hypotheses, said second position is completely reached when thearea T of the cross section of the prosthesis 12 is fully contained inthe area A of the tubular element 7.

In the case of elongated prosthesis 12, contained inside the suitablycounter-shaped seat 31, in said second position the first axis X-X ofthe channel Z is aligned with respect to the axis H-H of the seat 31.

Still more in detail, the axis H-H of the seat, and hence also the axisY-Y of the prosthesis 12, is parallel to the axis X-X of the channel Zand coincides with the same.

The arrangement of the axis of the prosthesis 12, hence of the seat 31,with respect to the channel Z allows obtaining the liquid communicationbetween the channel and the seat.

This allows, due to the subsequent action of the pressure element 16,described in more detail below, facilitating the insertion of theprosthesis 12 inside the channel Z and the subsequent exit from thechannel Z.

Below, the two embodiments of the device 1 are described, having severalcomponents in common; for this reason, they are only described onceduring the embodiment discussion.

In a first embodiment, the seat 31 is positioned above the pressureelement 16 which can be at least partly arranged in the chamber C.

More specifically, in such context of the first embodiment, the pressureelement 16 is arranged, before the applicator pistol starts to function,in a rest position (illustrated in FIG. 4).

In said rest position, the pressure element 16 can be at least partlyinside the chamber C.

In said rest position, the pusher element 13 pushes the seat 31 againstthe pressure element 16 by maintaining the latter in the first position.

In said rest position, the pressure element 16 is an obstacle to thefacilitated push, along the direction S, from the pusher element 13 ontothe seat 31.

As illustrated in FIG. 4, the pressure element 16 exits outward, withthe pointed end 17 thereof, from the tubular element 7 by an amount D1.

In such case, the pressure element 16 is completely inserted inside thechamber C, crossing the same in order to reach the channel Z of thetubular element 7, entirely crossing it.

The device 1 also comprises first movement means 21 in order to move thepressure element 16 inside the tubular element 7 parallel to the axisX-X.

The first movement means 21, common to both embodiments, can comprise afirst motor 22, e.g. of electric type, adapted to rotate a first wormscrew 23. The first worm screw 23 is in turn engaged with a carriage 24on which the pressure element 16 is mounted.

Said pressure element 16, in the first embodiment, is movable under theaction of first movement means 21 from the rest position to a retreatedposition and from the retreated position to a loading position.

In said retreated position, the pressure element 16 is disconnected fromthe chamber C in order to allow the pusher means to move, along thedirection S, the seat 31 in the second position.

The first movement means 21 facilitate the movement of the pressureelement 16, from the rest position to the retreated position (the lattervisible in FIG. 6).

In other words, the first movement means 21 are programmed for movingpressure element 16 back outside the tubular body 7 and the chamber C inorder to generate the liquid communication between the seat 31 and thechannel Z and to allow the pusher element 13 to push the seat 31 intothe second position, thus facilitating the alignment between theprosthesis 12 and the channel Z.

In the loading position, the pressure element 16 crosses the chamber Cand is close to pushing the prosthesis 12 inside the tubular element 7,i.e. inside the channel Z (see the final time instant of the position inFIG. 6)

The movement of the pressure element 16 from the rest position to theretreated position and from the retreated position to the loadingposition occurs through the action of the movement means 21 which willbe better described below.

In a second embodiment, the pressure element 16 is initially housedinside the applicator pistol 2 while in the cartridge 5, inside thetubular element 7, a closure element 15 is present.

The seat 31 is positioned on top of a passage 35 obtained in the supportbody 8, in which the locking element 15 is positioned. In particular,the locking element 15 is positioned inside the aforesaid passage 35during the initial instants, before the applicator pistol 2 starts tofunction.

Still more particularly, the locking element 15 is situated inside thetubular element 7 and at least partly crosses the interior of thechamber C in order to hinder the action of the pusher means 13.

In such time instant, the seat 31 is constrained in the first positionand the pressure element 16 is placed in a trigger position, in which itis disconnected from the channel Z and from the chamber C (FIG. 3).

Also in this embodiment, the movement of the pressure element 16 isentrusted to the first movement means 21.

Said movement means 21 facilitate the movement of the pressure element16 from the trigger position to an advance position, from the advanceposition to a retreated position and from the retreated position to aloading position.

The pressure element 16, from the trigger position to the advanceposition, slides under the action of the first movement means 21 insidethe tubular body 7 in order to expel locking element 15.

In such time instant, the pressure element 16 pushes the closure element15 outside the tubular element 7 and the passage 35 mentioned above issimultaneously and progressively occupied by the pressure element 16.

In this manner, the pusher element 13 continues to be opposed, this timeby the pressure element 16 which occupies the position previouslyoccupied by the closure element 15, and the seat 31 remains in its firstposition.

When the pressure element 16 has reached the advance position (FIG. 4),this will have crossed the entire chamber C, the channel Z of thetubular element 7 until it exits outward from the latter by apre-established amount D1.

As is visible from the enclosed figures, the rest position of the firstembodiment of the device 1 illustrated in FIG. 4 coincides with theadvance position of the second embodiment of the device.

The penetration portion of the pressure element 16 inside the channel Zwill be sized in a manner such to allow the pointed end 17 to exit fromthe tubular element 7, in a manner so as to allow both the automaticexpulsion of the closure element 15 from the tubular element 7 and thesubsequent possibility of penetrating the body tissue through thepointed end 17 of the pressure element 16.

The pressure element 16, having reached the advance position, willhinder the action of the pusher element 13.

Subsequently, according to the modes already described in the firstembodiment, the pressure element 16 will proceed under the action of themovement means 21 to be moved from the advance position to the retreatedposition and from the retreated position to the trigger position.

In the retreated position, no component will be present in the chamberC, neither the locking element 15 (previously expelled) nor the pressureelement 16 (situated in the retreated position), i.e. inside the passage35 arranged underneath the seat 31, the prosthesis 12 can be moved,under the action of the pusher element 13, from the first position tothe second position.

Having reached the second position, the prosthesis 12 and in particularthe axis H-H of the seat 31 will coincide with the axis X-X of thetubular body 7.

In such position, the pressure element 16, under the action of the firstmovement means 21, reaches the loading position and proceeds with theinsertion of the prosthesis 12 inside the channel Z until the expulsionof the same from the tubular element 7.

Second movement means 25 are also provided for, common to bothembodiments, in order to move the tubular element 7 with respect to thepressure element 16. The second movement means 25 can comprise a secondmotor 26, e.g. of electric type, adapted to rotate a second worm screw27. A slide 28, which supports the cartridge 5, is engaged with thesecond motor 26.

The first motor 22 and the second motor 26 are fixed to a support flange29 arranged in a rear region of the operative portion 4 of theapplicator pistol 2.

The first worm screw 23 and the second worm screw 26 are preferablyparallel to each other and are extended along a main size of theoperative portion 4. The first worm screw 23 and the second worm screw26 are arranged on both sides of the pressure element 16, when thelatter is received inside the applicator pistol 2.

The device 1 also comprises a control unit 30 for controlling the firstmovement means 21 and the second movement means 25. In the depictedexample, the control unit 30 is housed inside the grasping portion 3 ofthe applicator pistol 2. The control unit 30 allows preciselyprogramming the travel of the first movement means 21 and of the secondmovement means 25, and consequently of the pressure element 16 and ofthe tubular element 7.

Activation means, common to both embodiments, can be provided foractivating the first movement means 21 and the second movement means 22.The activation means can comprise a button 32 positioned in the graspingportion 3 of the applicator pistol 4. In one version, the activationmeans can also comprise a rear button 34, shown in FIG. 8, positioned ina rear region of the operative portion 4.

The device 1 can also comprise signaling means 33, common to bothembodiments, adapted to signal the status of the device 1 to anoperator. The signaling means 33 can for example inform the operatorthat the device 1 is ready to carry out a certain operation, or that theoperator must wait several seconds before carrying out any operationbecause the device 1 is currently working. The signaling means 33 can bepositioned in a rear region of the operative portion 4. The signalingmeans 33 can be of optical type and can comprise one or more coloredLED.

During functioning, the operator must actuate preliminary operationsaccording to the device 1 with which one intends to carry out theoperation.

A first device 1, obtained by utilizing the first embodiment, providesfor an applicator pistol 2 and a cartridge 5 already assembled together.

The device 1, according to the first embodiment, reaches an initialoperative position shown in FIG. 4 in which the pressure element 16 isin the rest position.

In this manner, it is possible to avoid employing the closure body 15,since the channel Z of the tubular body 7, and the chamber C, of thecartridge 5, are isolated from each other by the pressure element 16;the latter results at least partly inserted in the chamber C, and thusthe pusher element 13 is prevented from bringing the seat 31 of theprosthesis 12 from the first position to the second position.

The pressure element 16 is in the rest position, in which it exits fromthe tubular element 7 with its pointed end 17.

In such position, the pressure element 16, also situated inside thechamber C of the support body 8, hinders the pusher element 13,maintaining the seat 31 in the first position.

In the rest position, the seat 31, situated in the first position, ispushed by the elastic means 14 against the pressure element 16 whichblocks the movement S of the seat 31 from the first position to thesecond position. In such time instant, there is no liquid communicationbetween the channel Z and the chamber C, i.e. the prosthesis 12 isisolated.

In this step, the device 1, in particular the tubular element 7 is readyto be inserted in the body tissue.

The symmetric conformation of the pointed end 17 will facilitate theopening of the body tissue and thus the insertion of the tubular element7.

The insertion of the tubular element 7 is further facilitated by thesurface treatment of the external portion which is coated with TEFLON®or ceramic material. Such coating type reduces the friction between thetubular element 7 exterior and the tissue, in a manner so as to preventthe tubular element 7 exterior from adhering the tissue.

Once the correct position for the release of the prosthesis is reached,the operator activates the activation means, for example by pressing thebutton 32.

The control unit 30 automatically recognizes, through the use of knownelectronic signaling devices, that the device 1 utilizes the firstembodiment, i.e. it is of the type with cartridge and applicator pistolalready assembled by the manufacturer.

The control unit 30 drives the first motor 22 which correspondinglyrotates the first worm screw 23 in a direction such that the carriage 24moves back inside the operative portion 4. The pressure element 16 isconsequently moved in a retreated direction F1.

The first movement means 21 are programmed for moving the pressureelement 16 back.

In this manner, the pressure element 16 first exits from the interior ofthe tubular element 7 and subsequently moves back until it exits fromthe chamber C.

Such operative position is defined upon the attainment of the retreatedposition.

In such position, the seat 31 and in particular the prosthesis 12 aremoved along the movement direction S, being moved from the firstposition to the second position.

Said movement occurs under the action of the pusher element 13 whichencounters no more obstacles.

In such time instant, the prosthesis 12 is situated with its axis Y-Yaligned with the axis X-X of the chamber Z. Such position is shown inFIG. 5.

After the pressure element 16 has reached the retreated position, thecontrol unit 30 once again activates the first movement means 21 foradvancing the pressure element 16 in an advancement direction F, inorder to reach the loading position.

The subsequent driving of the movement means 21 and 22, after thepressure element 16 has reached the loading position, will be describedin the second embodiment of the device 1.

A second device 1, obtained by employing the second embodiment, providesfor an applicator pistol 2 and a cartridge 5 initially disassembled andpackaged inside separate casings, so as to both be in sterileconditions.

The pressure element 16 is positioned inside the applicator pistol 2completely disconnected from the channel Z and from the chamber C.

Said pressure element 16 is therefore positioned in the triggerposition.

The cartridge 5 contains at its interior the locking element 15, atleast partly crossing the chamber C, in order to hinder the pusherelement 13, maintaining the seat in the first position.

The cartridge 5 is mounted on the applicator pistol 2, positioning thesupport body 8 inside the hole 9 and pushing the cartridge 5 towards theinterior of the operative portion 4. In this manner, the fixing means 10associated with the cartridge 5 are engaged with the correspondingfixing means obtained in the applicator pistol 2, e.g. with the laminarelement 11, and the cartridge 5 results locked on the applicator pistol2.

The initial operative position shown in FIG. 3 is thus reached. In thisposition, the pressure element 16 is still housed inside the applicatorpistol 2 in the trigger position, at the rear of the cartridge 5. Thelocking element 15 is positioned inside the support body 8, inside thechamber C, and also partly inside the tubular element 7, inside thechannel Z. The locking element 15 closes the passage Z arranged belowthe seat 31, thus providing the liquid communication between the channelZ and the seat 31 and overcoming the resistance of the elastic means 14.In other words, the locking element 15 hinders the movement S of thepusher element 13 which remains in the first position.

In such time instant, the seat 31 is isolated by the channel Z of thetubular element 7.

The operator now activates the activation means, for example by pressingthe rear button 34 and maintaining it pressed until the first signalingelement is turned on, e.g. a red LED, of the signaling means 33. Thecontrol unit 30 is thus informed that the cartridge 5 was correctlypositioned in the applicator pistol 2.

The control unit 30 activates first movement means 21 for advancing thepressure element 16 inside the tubular element 7. In particular, thecontrol unit 30 acts on the first motor 22, which in turn drives theworm screw 23 in rotation. The latter moves the carriage 24 towards thefront terminal region 6 of the applicator pistol 2. The pressure element16, which is fixed with respect to the carriage 24, is thus advancedalong an advancement direction F and penetrates inside the tubularelement 7 in order to be moved from the trigger position to the advanceposition.

Here, the pressure element 16 interacts with the locking element 15.

The pressure element 16 pushes the locking element 15 and its pointedend 17 is inserted inside the hollow terminal section 15 a, facilitatingthe engagement of the pressure element 16 with the locking element 15.

The coupling between the pointed end 17 and terminal section 15 afacilitates the movement of the locking element without pointing insidethe tubular element.

During the movement of the pressure element 16 from the trigger positionto the advance position, the pressure element 16 continues toprogressively advance inside the tubular element 7, the pressure element16 pushes the locking element 15 along the advancement direction F untilit completely exits through the open end 18.

The first movement means 21 are programmed for moving the pressureelement 16 along a controlled travel. Indeed, the first movement means21 are programmed for being stopped when the pointed end 17 of thepressure element 16 projects outside the tubular element 7 by apre-established amount D1. In such a manner, the advance position shownin FIG. 4 is completed; in such position, the device 1 is ready tointeract with the body of the patient.

The operator can then penetrate the body tissue in which the prosthesis12 must be inserted, at the desired position. It is thus possible tointroduce, in the body tissue, first the portion of the pressure element16 that exits from the tubular element 7, and then, by continuing topress the pistol 2 towards the patient, a portion of the tubular element7 having a desired length.

It is observed that, since the pointed end 17 of the pressure element 16in this step exits from the tubular element 7, the body tissue ispenetrated by the pressure element 16, which behaves like a needle.

In addition, the axial-symmetric conformation of the pointed end 17facilitates an improved opening of the tissues.

The coating made of Teflon® or ceramic material of the external surfaceof the tubular element 7 reduces the friction as much as possible andcontributes to the ease of insertion of the tubular element itself inthe body tissue.

In the advance position shown in FIG. 4, the prosthesis 12 is stillhoused inside the seat 31 which does not result in liquid communicationwith the channel Z. Indeed, the pressure element 16, which is positionedinside the tubular element 7 in the advance position, has substitutedthe locking element 15 in contact with the prosthesis 12. The pressureelement 16 therefore maintains the prosthesis 12 pushed upward,overcoming the force exerted downward by the elastic means 14.

When the pressure element 16 has pierced body tissue and the tubularelement 7 has reached the position in which the prosthesis 12 must beimplanted, the operator can act on the activation means for once againactivating the first movement means 21. For such purpose, the operatorcan, for example, press the button 32 provided on the grasping portion 3of the applicator pistol 2.

The control unit 30 drives the first motor 22 in a rotation directionopposite that in which the first motor 22 was driven for expelling thelocking element 15. The first motor 22 correspondingly rotates the firstworm screw 23 in a direction such that the carriage 24 moves back insidethe operative portion 4. The pressure element 16 is consequently movedin a retreated direction F1 opposite the advancement direction F, whilethe operator maintains the applicator pistol 2 in contact with thepatient body, such that the tubular element 7 remains inside the bodytissue. In this manner, the pressure element 16 first returns inside thetubular element 7 and then moves back inside the operative portion 4,until it reaches the retreated position in which the passage Z arrangedbelow the seat 31 is left free. Such position is shown in FIG. 5.

When the pressure element 16 is situated in the retreated position, theprosthesis 12 is moved from the seat 31 inside the passage aligned withthe tubular element 7, due to the force exerted by the pusher element14. Such force is no longer opposed by the pressure element 16. Theprosthesis 12 is now aligned with the pressure element 16. Inparticular, the axis H-H of the seat 31 is aligned with the axis X-X ofthe channel Z.

After the pressure element 16 has reached the retreated position, thecontrol unit 30 once again activates the first movement means 21 foradvancing the pressure element 16 in the advancement direction F inorder to reach the loading position. The pointed end 17 of the pressureelement thus comes into contact with the rear end 20 of the prosthesis12 and, as the pressure element 16 is progressively moved along theadvancement direction F, the prosthesis 12 is pushed towards the openend 18 of the tubular element 7. The first movement means 21 areprogrammed for advancing the pressure element 16 until the front end 19of the prosthesis 12 is situated at a pre-established distance D fromthe open end 18 of the tubular element 7, the prosthesis 12 still beinghoused inside the tubular element 7. The distance D can be substantiallyzero, as shown in the example of FIG. 6, in which case the front end 19of the prosthesis 12 is substantially flush with the open end 18 of thetubular element 7.

In an alternative, non-depicted version, the distance D could be greaterthan zero, in which case the pressure element 16 would be stopped whenthe front end 19 of the prosthesis 12 is still inside the tubularelement 7.

After the pressure element 16 has positioned the prosthesis 12 at thedesired distance D from the open end 18, reaching the advance positionshown in FIG. 6, the control unit 30 activates the second movement means25. In particular, the control unit 30 acts on the second motor 26,which rotates the second worm screw 27 so as to move the slide 28 backin the retreated direction F1. Since the slide 28 is fixed with respectto the cartridge 5, the entire cartridge 5 is moved back inside theoperative portion 4. Consequently, the tubular element 7 is moved in theback direction F1 with respect to the pressure element 16, which insteadremains in a fixed position.

The release position shown in FIG. 7 is thus achieved; in this position,the prosthesis 12 is released in the body tissue in which the pressureelement 16 is inserted.

The second movement means 25 are programmed for stopping the travel ofthe pressure element 16 in the retreated direction F1 when the rear end20 of the prosthesis 12 has exited from the open end 18.

In particular, the second movement means 25 can be programmed for movingthe tubular element 7 back an amount equal to the longitudinal size DLof the prosthesis 12, increased by the distance D shown in FIG. 6. Inthis manner, the tubular element 7 is stopped when its open end 18 isflush with the rear end 20 of the prosthesis 12.

After the prosthesis 12 was released in the body tissue, it is possible,particularly if the tubular element 7 does not contain other prostheses,to once again advance the tubular element 7 in order to bring thecartridge 5 into the initial position, due to the second movement means25. The first movement means 21 can instead once again move the pressureelement 16 back inside the operative portion 4, such that the pressureelement 16 is disengaged from the cartridge 5. In this manner, the finalposition shown in FIG. 8 is reached. The operator can now remove thecartridge 5 from the applicator pistol 2.

The first movement means 21 and the second movement means 25 allowprecisely controlling the sequence with which the pressure element 16and the tubular element 7 are moved as well as the respectivetravels/paths.

In this manner, it is possible to prevent, in the release position shownin FIG. 7, the tubular element 7 from moving back too little or too muchwith respect to the pressure element 16, causing a partial release ofthe prosthesis 12.

Even if the cartridge 5 shown in FIGS. 1-8 contains a single prosthesis12, it is possible, in a non-depicted version, to provide for cartridgescontaining multiple prostheses, e.g. positioned on top of each other ina manner such to be introduced in successive instants inside the tubularelement 16. Such prostheses can then be implanted in the body of thepatient by repeating the previously described cycle several times.

The invention claimed is:
 1. A device for implanting a prosthesis in abody tissue, comprising: a tubular element, at its own interior defininga channel (Z) having extension direction along an axis (X-X) and crosssection of area (A), within which a prosthesis can slide that has across section of area (T); a pressure element movable inside the channel(Z) for moving said prosthesis; characterized in that it comprises: acartridge provided with a chamber (C), in communication with the channel(Z), comprising a seat, preferably with extension direction along anaxis (H-H) and cross section of area (V), housing the prosthesis andmovable inside the chamber (C); a pusher element operating on the seatin order to facilitate the movement of the seat inside the chamber (C)from a first position, in which the area (V) of the cross section of theseat is outside the area (A) of the cross section of the tubularelement, the seat not facing the channel (Z), to a second position, inwhich the area (V) of the cross section of the seat at least partlyintersects the area (A) of the cross section of the tubular element,inducing a communication between the channel (Z) and the seat suitablefor facilitating the insertion of the prosthesis inside the channel (Z)upon command of the pressure element.
 2. The device according to claim1, characterized in that said prosthesis, housed inside the seat, ismovable under the action of the pusher element from the first position,in which the area (T) of the cross section of the prosthesis is outsidethe area (A) of the cross section of the tubular element, to the secondposition, in which the area (T) of the cross section of the prosthesisis entirely contained inside the area (A) of the cross section of thetubular element in order to facilitate the insertion of the prosthesisinside the channel (Z) through the pressure element.
 3. The deviceaccording to claim 2, characterized in that said prosthesis preferablyhas an extension direction along an axis (Y-Y).
 4. The device accordingto claim 3, characterized in that said prosthesis is movable, under theaction of the pusher element, from the first position, in which the axis(Y-Y) is misaligned with the axis (X-X) of the channel (Z), to thesecond position, in which the axis (Y-Y) is aligned with the axis (X-X)of the channel (Z).
 5. The device according to claim 1, characterized inthat said pressure element is situated, in a first embodiment, in a restposition in which it is inserted inside the chamber (C), in order tohinder the pusher means, maintaining seat in the first position, so thatit exits outward from the channel (Z) for a pre-established amount (D1).6. The device according to claim 5, characterized in that said pressureelement, when situated in the rest position, is movable under the actionof first movement means from a retreated position, in which the pressureelement is disconnected from the chamber (C) in order to allow the seatto reach the second position, to a loading position, in which thepressure element crosses the chamber (C), pushing the prosthesis insidethe tubular element.
 7. The device according to claim 6, characterizedin that said first movement means are programmed for moving the pressureelement back outside the chamber (C) in order to generate acommunication between the seat and the channel (Z) and to allow thepusher element to push the seat into the second position, facilitatingthe alignment between the prosthesis and the channel (Z).
 8. The deviceaccording to claim 6, characterized in that said pusher element isdefined by elastic means suitable for generating a thrust of the seatfrom the first position to the second position, said pressure element,when situated in the retreated position, frees the elastic means,allowing the seat to reach the second position.
 9. The device accordingto claim 5, characterized in that said pusher element is defined byelastic means suitable for generating a thrust of the seat from thefirst position to the second position, said pressure element, whensituated in rest position, opposes the thrust exerted by the elasticmeans on the seat, constraining the latter in the first position. 10.The device according to claim 1, characterized in that it comprises, ina second embodiment, a closure element situated inside the tubularelement, at least partly crossing the interior of the chamber (C) inorder to hinder the action of the pusher means, thus maintaining theseat in the first position; said pressure element being positioned in atrigger position in which it is disconnected from the channel (Z) andfrom the chamber (C).
 11. The device according to claim 10,characterized in that said pressure element, when situated in thetrigger position, is movable under the action of first movement meansfrom an advance position, in which the pressure element crosses thechamber (C) and the channel (Z) of the tubular element, causing theoutward exit of the closure element from the tubular element, to aretreated position, in which the pressure element is disconnected fromthe chamber (C) in order to allow the seat to reach the second position,to a loading position, in which the pressure element crosses the chamber(C), pushing the prosthesis inside the tubular element.
 12. The deviceaccording to claim 11, characterized in that said first movement meansare programmed for advancing the pressure element inside the tubularelement in order to cause the outward exit of the closure element fromthe latter and the consequent removal of the same.
 13. The deviceaccording to claim 11, characterized in that said pusher element isdefined by elastic means suitable for generating a thrust of the seatfrom the first position to the second position, said pressure element,when situated in the advance position, opposes the thrust exerted by theelastic means on the seat, constraining the latter in the firstposition.
 14. The device according to claim 10, characterized in thatsaid pusher element is defined by elastic means suitable for generatinga thrust of the seat from the first position to the second position,said closure element, when inserted in the tubular element, opposes thethrust exerted by the elastic means on the seat, constraining the latterin the first position.
 15. The device according to claim 1,characterized in that said pusher element is defined by elastic meanssuitable for generating a thrust of the seat from the first position tothe second position.
 16. The device according to claim 15, characterizedin that said elastic means cause a thrust of the seat along a direction(S) incident on the axis (X-X) of the channel (Z).